Mizuho Kazami, a beautiful young woman, went to a high school in mountainous area to teach Japanese. However, she is actually a representative from galaxy association on her mission to observe earth. Accidentally, Kei Kusanagi, one of her student, discovered her true identity. In order to keep it secret, Mizuho Kazami married Kei Kusanagi and they both live together secretly. Can they keep their marriage from Kei's classmates?